1. Field of the Invention
The present invention relates to a method for suppressing noise in an electronic apparatus, in which assembling efficiency is improved, the configuration is simple, and the cost is low.
2. Description of the Related Art
As a method for suppressing EMI (it is an abbreviation for xe2x80x9cElectromagnetic Interferencexe2x80x9d and will be referred to as xe2x80x9cnoisexe2x80x9d) in an electronic apparatus such as a communication apparatus, a shielding method utilizing a metal chassis has been generally known. The metal chassis is formed by joining a plurality of shielding plates to each other.
In the metal chassis comprising the plurality of shielding plates, it is difficult to eliminate a seam (gap) between the shielding plates in manufacturing. Such a joint gap serves as an internal-noise radiation source. When the shielding plates do not come into contact with each other with low impedance, the impedance of one plate is unmatched to that of the other one. The shielding plate in a high impedance state serves as a noise radiation antenna. Consequently, noise is not suppressed in some cases.
To solve such a problem, as disclosed in Japanese Unexamined Patent Publication (JP-A) No. H9-186480, a metallic contact called a xe2x80x9cfingerxe2x80x9d (the detail thereof will be described below) is inserted into a joint gap between the shielding plates, or conductive Monel metal is fixed to the shielding plates to be joined to each other by double-faced tape to make both shielding plates conductive, thereby reducing the contact impedance.
Furthermore, as disclosed in Japanese Unexamined Patent Publication (JP-A) No. H10-200284, the following shielding configuration (the detail thereof will be described below) of an electronic apparatus has been proposed. That is, a shielding member comprises a coil spring and a core member and the shielding member is fitted into a chassis by a fixing member.
However, the conventional method for suppressing noise in an electronic apparatus such as a communication apparatus has the following problems.
In the electronic apparatus such as a communication apparatus, the above-mentioned noise suppression is performed. The attachment of such a countermeasure component against the noise suppression takes much time. In addition, the conductive Monel metal is easily detached from the plate. Fixing should be performed after first determining the length of the Monel metal. Accordingly, the yield is low. Since the component is exclusively used, the cost is high.
Accordingly, it is an object of the present invention to provide a method for suppressing noise in an electronic apparatus, in which assembling efficiency is improved.
Another object of the present invention is to provide a method for suppressing noise in an electronic apparatus with a simple configuration.
Still another object of the present invention is to provide a method for suppressing noise in an electronic apparatus with low cost.
According to one aspect of the present invention, there is provided a method for suppressing noise in an electronic apparatus which is shielded with a metal chassis including shielding plates, the method comprising the steps of: forming notches on an end of a specific one of the shielding plates; compressing coil springs and fitting the coil springs into the notches; and jointing the end of the shielding plate to another shielding plate.
According to another aspect of the present invention, there is provided a method for suppressing noise in an electronic apparatus including shielding plates for shielding the electronic apparatus, the method comprising the step of: sandwiching a sealing unit, in which coil springs are compressed and then fitted into notches, between the shielding plates.